We present an approach based on a pretopological formalism that allows the
mathematical modeling of image segmentation by region growing. The choice o
f pretopology is motivated by the fact that it has less axioms than the top
ology which facilitates its adaptation to discrete spaces and in particular
ly image processing. In our approach, the pretopological adherency function
associated to the pretopological structure is defined by a criterion of ho
mogeneity. We apply our approach to the extraction of handwritten informati
on on check background with images of scene and to edge detection. The aggr
egation from chosen initial germ. ends to a closed part of the image compos
ed by a stroke (a line of handwriting) or a line of contours. The evaluatio
n, undertaken on 60 checks with various background images and different ima
ges, gives 92% of good results for the extracted handwriting with a complet
e elimination of the background and good results for edge detection.